What's the advantage of cooking something in parchment or banana leaf? The food--be it fish, chicken, or vegetables--steams in its own juices, sealing in all the fantastic flavors of the herbs and other seasonings it's being cooked with. Three other reasons to steam in leaves or parchment (in case you need them!): It's incredibly easy, steaming is an excellent way to retain the nutrients in your protein and veg, and we just love opening up that little bundle on our plates, breathing in the amazing aromas.